The present invention relates to a simplified method for preparing halogenated alkenone ethers.
Halogenated alkenone ethers, such as 4-ethoxy-1,1,1-trifluoro-3-butenone, are building blocks in chemical synthesis, as disclosed, for example, in U.S. Pat. No. 5,708,174 (=EP 744,400). They may be prepared by reacting an acid chloride with a vinyl ether in the presence of a base, as described in the aforementioned U.S. patent. For this reaction, the base may also be used in excess as a solvent. It is known, for example, from N. D. Field and D. H. Lorenz, High Polymer, 1970, page 394 that the reaction of phosgene with vinyl ethers in the absence of a base leads to polymerization.